Previous investigations have demonstrated the role of uveal tract cells in producing antibody to intravitreally injected protein antigens. The ability of various agents to enhance or suppress ocular antibody production has been established. The proposed investigations will further establish the role of T and B lymphocytes in ocular immune reactions, and clarify the mechanisms of Cyclophosphamide induced suppression. Specific objectives of the proposed project are 1) To identify T and B lymphocytes in the ocular and lymph node tissue of normal and intravitreally immunized rabbits. Tests will be performed on suspensions prepared from uveal tract and lymph nodes and on fixed tissue sections from the same sources. 2) To separate pure T and B cell populations from lymph node and uveal tract cell suspensions. 3) To further characterize the separated cells by functional analyses. Tests used will include assays for antiboy dependent cellular cytotoxicity, and the response to T and B cell mitogens. 4) To determine the nature and function of lymphocytes present in the eyes of rabbits whose secondary ocular immune response has been suppressed by Cyclophosphamide. 5) To further investigate the response of guinea pigs after intravitreal immunization with ovalbumin. To determine whether guinea pigs that did not produce detectable antibody after a single intravitral injection have, in fact been primed for a secondary response.